Vanilla flavours are among some of the most frequently used flavours worldwide. They are used for the flavouring of numerous foods such as ice-cream, dairy products, desserts, confectionary, bakery products and spirits. They are also used in perfumes, pharmaceuticals and personal hygiene products.
Natural vanilla flavour has been obtained traditionally from the fermented pods of Vanilla orchids. It is formed mainly after the harvest during several weeks of a drying and fermentation process of the beans by hydrolysis of the vanillin glucoside that is present in the beans. The essential aromatic substance of vanilla flavour is vanillin (4-hydroxy-3-methoxybenzaldehyde).
Apart from natural vanilla flavor obtained from fermented vanilla pods, biotech and chemical synthetic processes have also been developed to produce biotechnologically and synthetically produced vanillin which is also used for the flavouring of foods. Several potential feedstocks have been suggested for the production of natural vanillin. By way of example, it has been found that many substrates such as ferulic acid, lignin, vanillic acid, eugenol and isoeugenol can be transformed to vanillin using many diffident microorganisms. Some of the highest yields of vanillin are obtained using a Streptomyces setonii strain capable of converting ferulic acid to natural vanillin (see, for example, EP0885968B and Muheim and Lerch (1999) Appl Microbiol Biotechnol 51: 456-461). However, as ferulic acid (from rice hull starting material) is an expensive starting material there is a need to identify cheaper ferulic acid precursor starting materials and efficient bioconversion processes for making ferulic acid useful in the preparation of natural vanillin of high flavor quality.
According to legislation to regulate the sale of natural food products, only products obtained from plant and animal materials or obtained from microbial enzymatic biotransformations/biocatalysis can be identified as natural. This regulatory legislation can vary from country to country. By way of example, US natural vanillin is derived from eugenol by a process which is not accepted as natural in the EU. The launch of a natural vanillin product/food ingredient made from a new starting material in the EU is subject to close scrutiny to ensure compliance with the local regulatory legislation and to protect the consumer from a vanillin ingredient which has not been made using regulatory acceptable methods.
Given that the customer-led demand for natural vanilla flavour or for vanillin isolated from the vanilla beans is very high and that the processes for making synthetic vanillin are much less expensive than the traditional process, the problem of falsification and misleading information is a particularly large one. Consumer organisations regularly publish the results of studies on the genuineness of vanilla flavour declared as natural in foods. These evaluations are typically based on analytical results. However, it has become clear that interpretation of the analytical results without knowledge of the production conditions or influencing factors in particular cases can lead to false evaluations and the incorrect designation of a product as synthetic when in fact it may be produced from plant and animal materials or obtained from microbial enzymatic biotransformations/biocatalysisn and is thus entitled to be deemed a natural product.
Because of the consumer led demand for natural products such as natural vanillin, there is an increasing need for the efficient production of natural vanillin by biotransformation/bioconversion processes which: (i) use raw materials of natural origin; and (ii) employs process steps which are compatible with the requirements for natural flavours as recognized by the industry and regulatory authorities. There is also a need for the assessment of suitable methods for authenticating that the end product is a true natural vanillin product. The present disclosure seeks to provide for such biosynthesis/bioconversion processes and methods.